Airbag control unit with part number 5WK44315

What is the function of the Airbag Control Unit 5WK44315?

The Airbag Control Unit 5WK44315 is the central safety module specifically calibrated for the Renault Fluence I. It continuously monitors all relevant vehicle sensors and is responsible for precisely and rapidly activating occupant restraint systems—such as airbags and seatbelt pretensioners—in the event of a collision.

As the brain of the passive safety system, this control unit processes data from acceleration and yaw rate sensors. Based on this information, it determines whether a collision has occurred and which restraint devices need to be deployed to provide optimal protection for occupants.

After deployment, the unit permanently stores crash data. This feature serves as a safety safeguard, requiring a system check after an accident and preventing further use without inspection.

Why does the 5WK44315 control unit fail?

The most common reason for repairing the 5WK44315 control unit is not a technical malfunction, but rather the storage of crash data following an accident. This data retention is a manufacturer‑specified safety feature that locks the control unit, preventing reuse without professional servicing.

Even if the control unit remains fully functional electronically, the fault memory cannot be cleared using standard diagnostic tools after a crash. The airbag warning light stays illuminated, and the system becomes inoperable. In such cases, repair involves a professional “crash reset” that erases accident data and restores factory settings.

It is crucial that only unopened control units are sent in for successful repair. Previous improper repair attempts can damage internal electronics, making proper restoration impossible.

How do you recognize a defect in the 5WK44315?

A typical defect of the 5WK44315 control unit primarily manifests as the airbag warning light remaining constantly illuminated on the instrument cluster. Additionally, the fault memory—especially the entry indicating “crash data stored”—cannot be cleared with standard workshop diagnostics, signaling that the system has already been triggered.

The most obvious symptom is the persistently lit airbag warning light. It does not turn off after starting the engine, indicating that the entire restraint system is disabled and would not deploy in another collision.

During a diagnostic scan, an error code often appears directly referencing stored crash data. Attempts to clear this error fail because the control unit is internally locked. While communication with the device remains possible in these situations, the critical function needed to erase the fault is blocked.

In which vehicles is the 5WK44315 installed?

The airbag control unit with part number 5WK44315 is specifically designed for Renault models. It is mainly used in the first generation of the Renault Fluence, manufactured during a specific production period.

At Airbag24, we repair the 5WK44315 control unit for the following model, with compatibility covering the entire series:

Renault Fluence I (model years 2009–2018)

How is the 5WK44315 professionally repaired?

Professional repair of the 5WK44315 at Airbag24 focuses on safely resetting the stored crash data. This process restores the control unit’s internal software to its pre-crash state, ensuring full functionality once again. Each repair comes with 2 years' statutory liability for defects.

Upon receipt of the removed, unopened control unit, an initial inspection is performed. This is followed by a specialized “crash reset,” which clears accident‑related entries directly from the unit’s memory without altering the vehicle‑specific calibration. This ensures the control unit is immediately ready for installation (plug-and-play) after replacement.

Finally, the unit undergoes a comprehensive functional and quality check to verify the correct operation of all system components. Repairs are carried out using procedures aligned with factory specifications.

What are the benefits of repair?

The key advantage of repairing the 5WK44315 lies in significant cost savings—up to 70% compared to purchasing a new unit from the manufacturer. Moreover, there is no need for time‑consuming re‑coding, as the original vehicle configuration is preserved and the unit becomes operational right away.

Since this is usually a purely data‑related issue, repair offers a technically sound and sustainable solution. The original, proven hardware of the control unit is reused, benefiting both your wallet and the environment. The included 2-year statutory liability for defects provides added security and underscores the high quality of the service.